Electrical equipment having a heat-generating component includes various apparatuses, such as arc welders, are cutters, electrical chargers, and power supply apparatuses for communications devices and plating devices. Such electrical equipment is provided with a fan for cooling the heat-generating component. One example of the power supply apparatuses having a fan is shown in Australian Patent No. 674,633 issued on Apr. 22, 1997 (corresponding to U.S. patent application No. 08/554,529 filed on Nov. 7, 1995).
The power supply apparatus disclosed in the Australian patent has a housing in which a power supply circuit for converting AC power to DC power is disposed. The housing has a front panel formed with a plurality of air-intake apertures and a rear panel formed with a plurality of air-outlet apertures. A fan is also disposed in the housing. The fan is driven to draw air into the housing through the air-intake apertures. The air flows over heat-generating components, such as a transformer, a smoothing reactor, and a heat-dissipating fin on which semiconductor switching components are mounted, and cools them. Then, the air is driven to flow out of the housing through the air-outlet apertures.
The fan is driven during the operation of the power supply apparatus. Therefore, when the power supply apparatus is used for a long time, e.g. several months, dust may be deposited around the air-intake apertures. Such dust reduces the amount of air drawn into the housing, and thus prevents the heat-generating components from being efficiently cooled. Insufficient cooling of the components may result in failure of the power supply circuit. This problem may be raised not only in DC power supply apparatus but also any electrical equipment in which air is drawn in through an air-intake aperture for cooling. A cooling apparatus according to the present invention is used for solving the above-stated problem.